From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id B24BB4B259 for ; Wed, 5 Jun 2024 18:37:24 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id E923E68D60D; Wed, 5 Jun 2024 21:37:20 +0300 (EEST) Received: from mail-pg1-f176.google.com (mail-pg1-f176.google.com [209.85.215.176]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 7AC8F68D4AF for ; Wed, 5 Jun 2024 21:37:14 +0300 (EEST) Received: by mail-pg1-f176.google.com with SMTP id 41be03b00d2f7-6cc3e134f88so88278a12.0 for ; Wed, 05 Jun 2024 11:37:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1717612632; x=1718217432; darn=ffmpeg.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=VbeghcEZfSZN0vwNyX8Wt2paalh6ndUelgoWgRH5lNE=; b=jxbxmQx1ClhfyL6TQW4TWdbBl5/7dVsfPKvK+Az3+OVxotlBCg6skJlwLKebxtrz8v TDfjkgSh/uMPPNyPs74nrdEVT/9KhVC+l8ceLsNHYqo5mDPvNlzYKUAMxJ1NzKqLpvlg RX5F6Fo+ATgDrqPtHF2xFcV4SrX/TU6F1nsKpU0BDSLdDDS4T0JzRZ0OtRGEm94r5DmU y2IZZizj67I8UcVOJ9NO+8LpalRNmHeIh+GSJIIeWOqS8J5iu8sajYtiDKwDsZyoMpwa Y0W/unYjxyChRAb7pgAikEa0qExmmQAySqQt/bd8EIRHY3oqPD/tovzaYi0hVNcn2YqX Q49A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717612632; x=1718217432; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=VbeghcEZfSZN0vwNyX8Wt2paalh6ndUelgoWgRH5lNE=; b=Oto0k4Yz9raCU1WobsUgEKZCgrqEabdGIZ63TsCd8HZzI5d0c3pvO8g8tCgY7ChASo +phOAPq+Iki55CYgL9e6bm7NOAOVncjIPrsXcgNwosafrE1nnplIcePnMxJNomSeaJjT jiTxx0QE0fUN/Zxy8HatTK2wRIre2r2WgHCxdgWVCOk1i3oRB+CWJogCUJ5xKmiCUZiK M/9J0AHJohHAGu/53bRYOW/+sT8ITMN3F3F7TEhAvnHFN7s59IkviI+sqsVJcbGC3mgI bzCAuKuREjv4miVkoMCZuP1Htm/MwureAttex90SugADFshC9eIK0TLvQ2jUfbmzn1wj MHvg== X-Gm-Message-State: AOJu0YyWW2iAKRJKAeVlMl0qsJim42W1h9psKynN20LkbiEsRW0jsgDe wJykbt48U+EsKpIvn4WmN+PNoSZByJq/eaziNmWVEZUwUH+qmZtLRxSmmg== X-Google-Smtp-Source: AGHT+IHkKaX2LaCLTTOFZl98RQIuq0SVS9oe7keds+E85FyziNYz4QLEQP8tJDaI/LrRUg7Tkz8q3g== X-Received: by 2002:a17:90a:e618:b0:2c2:4114:cf49 with SMTP id 98e67ed59e1d1-2c27db18c10mr4082539a91.26.1717612632064; Wed, 05 Jun 2024 11:37:12 -0700 (PDT) Received: from localhost ([2601:647:6880:6810:25d5:c0d6:d68f:daba]) by smtp.gmail.com with UTF8SMTPSA id 98e67ed59e1d1-2c254a78869sm2569094a91.0.2024.06.05.11.37.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 05 Jun 2024 11:37:11 -0700 (PDT) From: Connor Worley To: ffmpeg-devel@ffmpeg.org Date: Wed, 5 Jun 2024 11:37:07 -0700 Message-ID: <20240605183708.61690-1-connorbworley@gmail.com> X-Mailer: git-send-email 2.43.1 MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH v7 1/2] lavu/hashtable: create generic robin hood hash table X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Cc: Connor Worley Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Signed-off-by: Connor Worley --- libavutil/Makefile | 2 + libavutil/hashtable.c | 192 ++++++++++++++++++++++++++++++++++++ libavutil/hashtable.h | 91 +++++++++++++++++ libavutil/tests/hashtable.c | 110 +++++++++++++++++++++ 4 files changed, 395 insertions(+) create mode 100644 libavutil/hashtable.c create mode 100644 libavutil/hashtable.h create mode 100644 libavutil/tests/hashtable.c diff --git a/libavutil/Makefile b/libavutil/Makefile index 6e6fa8d800..8c7b4452b4 100644 --- a/libavutil/Makefile +++ b/libavutil/Makefile @@ -138,6 +138,7 @@ OBJS = adler32.o \ fixed_dsp.o \ frame.o \ hash.o \ + hashtable.o \ hdr_dynamic_metadata.o \ hdr_dynamic_vivid_metadata.o \ hmac.o \ @@ -252,6 +253,7 @@ TESTPROGS = adler32 \ file \ fifo \ hash \ + hashtable \ hmac \ hwdevice \ integer \ diff --git a/libavutil/hashtable.c b/libavutil/hashtable.c new file mode 100644 index 0000000000..155a264665 --- /dev/null +++ b/libavutil/hashtable.c @@ -0,0 +1,192 @@ +/* + * Generic hashtable + * Copyright (C) 2024 Connor Worley + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include +#include + +#include "crc.h" +#include "error.h" +#include "mem.h" +#include "hashtable.h" + +#define ALIGN _Alignof(size_t) + +struct AVHashtableContext { + size_t key_size; + size_t key_size_aligned; + size_t val_size; + size_t val_size_aligned; + size_t entry_size; + size_t max_entries; + size_t utilization; + const AVCRC *crc; + uint8_t *table; + uint8_t *swapbuf; +}; + +#define ENTRY_PSL(entry) (entry) +#define ENTRY_OCC(entry) (ENTRY_PSL(entry) + FFALIGN(sizeof(size_t), ALIGN)) +#define ENTRY_KEY(entry) (ENTRY_OCC(entry) + FFALIGN(sizeof(size_t), ALIGN)) +#define ENTRY_VAL(entry) (ENTRY_KEY(entry) + ctx->key_size_aligned) + +#define KEYS_EQUAL(k1, k2) !memcmp(k1, k2, ctx->key_size) + +int av_hashtable_alloc(struct AVHashtableContext **ctx, size_t key_size, size_t val_size, size_t max_entries) +{ + struct AVHashtableContext *res = av_malloc(sizeof(struct AVHashtableContext)); + if (!res) + return AVERROR(ENOMEM); + res->key_size = key_size; + res->key_size_aligned = FFALIGN(key_size, ALIGN); + res->val_size = val_size; + res->val_size_aligned = FFALIGN(val_size, ALIGN); + res->entry_size = FFALIGN(sizeof(size_t), ALIGN) + + FFALIGN(sizeof(size_t), ALIGN) + + res->key_size_aligned + + res->val_size_aligned; + res->max_entries = max_entries; + res->utilization = 0; + res->crc = av_crc_get_table(AV_CRC_32_IEEE); + if (!res->crc) { + av_hashtable_freep(&res); + return AVERROR_BUG; + } + res->table = av_calloc(res->max_entries, res->entry_size); + if (!res->table) { + av_hashtable_freep(&res); + return AVERROR(ENOMEM); + } + res->swapbuf = av_calloc(2, res->key_size_aligned + res->val_size_aligned); + if (!res->swapbuf) { + av_hashtable_freep(&res); + return AVERROR(ENOMEM); + } + *ctx = res; + return 0; +} + +static size_t hash_key(const struct AVHashtableContext *ctx, const void *key) +{ + return av_crc(ctx->crc, 0, key, ctx->key_size) % ctx->max_entries; +} + +int av_hashtable_get(const struct AVHashtableContext *ctx, const void *key, void *val) +{ + size_t hash = hash_key(ctx, key); + + if (!ctx->utilization) + return 0; + + for (size_t psl = 0; psl < ctx->max_entries; psl++) { + size_t wrapped_index = (hash + psl) % ctx->max_entries; + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(entry) || *(size_t*)ENTRY_PSL(entry) < psl) + return 0; + if (KEYS_EQUAL(ENTRY_KEY(entry), key)) { + memcpy(val, ENTRY_VAL(entry), ctx->val_size); + return 1; + } + } + return 0; +} + +int av_hashtable_set(struct AVHashtableContext *ctx, const void *key, const void *val) +{ + int swapping = 0; + size_t psl = 0; + size_t hash = hash_key(ctx, key); + uint8_t *set = ctx->swapbuf; + uint8_t *tmp = ctx->swapbuf + ctx->key_size_aligned + ctx->val_size_aligned; + + memcpy(set, key, ctx->key_size); + memcpy(set + ctx->key_size_aligned, val, ctx->val_size); + + for (size_t i = 0; i < ctx->max_entries; i++) { + size_t wrapped_index = (hash + i) % ctx->max_entries; + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(entry) || (!swapping && KEYS_EQUAL(ENTRY_KEY(entry), set))) { + if (!*ENTRY_OCC(entry)) + ctx->utilization++; + *(size_t*)ENTRY_PSL(entry) = psl; + *ENTRY_OCC(entry) = 1; + memcpy(ENTRY_KEY(entry), set, ctx->key_size_aligned + ctx->val_size); + return 1; + } + if (*(size_t*)ENTRY_PSL(entry) < psl) { + if (ctx->utilization == ctx->max_entries) + return 0; + swapping = 1; + // set needs to swap with entry + memcpy(tmp, ENTRY_KEY(entry), ctx->key_size_aligned + ctx->val_size); + memcpy(ENTRY_KEY(entry), set, ctx->key_size_aligned + ctx->val_size); + FFSWAP(uint8_t*, set, tmp); + FFSWAP(size_t, psl, *(size_t*)ENTRY_PSL(entry)); + } + psl++; + } + return 0; +} + +int av_hashtable_delete(struct AVHashtableContext *ctx, const void *key) +{ + uint8_t *next_entry; + size_t hash = hash_key(ctx, key); + + if (!ctx->utilization) + return 0; + + for (size_t psl = 0; psl < ctx->max_entries; psl++) { + size_t wrapped_index = (hash + psl) % ctx->max_entries; + uint8_t *entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(entry) || *(size_t*)ENTRY_PSL(entry) < psl) + return 0; + if (KEYS_EQUAL(ENTRY_KEY(entry), key)) { + *ENTRY_OCC(entry) = 0; + for (psl++; psl < ctx->max_entries; psl++) { + wrapped_index = (hash + psl) % ctx->max_entries; + next_entry = ctx->table + wrapped_index * ctx->entry_size; + if (!*ENTRY_OCC(next_entry) || !*(size_t*)ENTRY_PSL(next_entry)) { + ctx->utilization--; + return 1; + } + memcpy(entry, next_entry, ctx->entry_size); + (*(size_t*)ENTRY_PSL(entry))--; + *ENTRY_OCC(next_entry) = 0; + entry = next_entry; + } + } + }; + return 0; +} + +void av_hashtable_clear(struct AVHashtableContext *ctx) +{ + memset(ctx->table, 0, ctx->entry_size * ctx->max_entries); +} + +void av_hashtable_freep(struct AVHashtableContext **ctx) +{ + if (*ctx) { + av_freep(&(*ctx)->table); + av_freep(&(*ctx)->swapbuf); + } + av_freep(ctx); +} diff --git a/libavutil/hashtable.h b/libavutil/hashtable.h new file mode 100644 index 0000000000..8ce6faafe3 --- /dev/null +++ b/libavutil/hashtable.h @@ -0,0 +1,91 @@ +/* + * Generic hashtable + * Copyright (C) 2024 Connor Worley + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVUTIL_HASHTABLE_H +#define AVUTIL_HASHTABLE_H + +#include + +/* Implements a hash table using Robin Hood open addressing. + * See: https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf + */ + +struct AVHashtableContext; + +/** + * Creates a fixed-sized Robin Hood hash table. + * + * @param ctx context to allocate and initialize + * @param key_size size of key type in bytes + * @param val_size size of value type in bytes + * @param max_entries maximum number of key-value pairs to store + * + * @return zero on success, nonzero on error + */ +int av_hashtable_alloc(struct AVHashtableContext **ctx, size_t key_size, size_t val_size, size_t max_entries); + +/** + * Looks up a value from a hash table given a key. + * + * @param ctx hash table context + * @param key pointer to key data + * @param val destination pointer for value data + * + * @return 1 if the key is found, zero if the key is not found + */ +int av_hashtable_get(const struct AVHashtableContext *ctx, const void *key, void *val); + +/** + * Stores a value in a hash table given a key. + * + * @param ctx hash table context + * @param key pointer to key data + * @param val pointer for value data + * + * @return 1 if the key is written, zero if the key is not written due to the hash table reaching max capacity + */ +int av_hashtable_set(struct AVHashtableContext *ctx, const void *key, const void *val); + +/** + * Deletes a value from a hash table given a key. + * + * @param ctx hash table context + * @param key pointer to key data + * + * @return 1 if the key is deleted, zero if the key is not deleted due to not being found + */ +int av_hashtable_delete(struct AVHashtableContext *ctx, const void *key); + +/** + * Deletes all values from a hash table. + * + * @param ctx hash table context + */ +void av_hashtable_clear(struct AVHashtableContext *ctx); + +/** + * Frees a hash table. + * + * @param ctx hash table context + */ +void av_hashtable_freep(struct AVHashtableContext **ctx); + +#endif diff --git a/libavutil/tests/hashtable.c b/libavutil/tests/hashtable.c new file mode 100644 index 0000000000..1e37d7663b --- /dev/null +++ b/libavutil/tests/hashtable.c @@ -0,0 +1,110 @@ +/* + * Generic hashtable tests + * Copyright (C) 2024 Connor Worley + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include + +#include "libavutil/avassert.h" +#include "libavutil/hashtable.h" + +int main(void) +{ + struct AVHashtableContext *ctx; + uint8_t k; + uint64_t v; + + // impossibly large allocation should fail gracefully + av_assert0(av_hashtable_alloc(&ctx, -1, -1, -1) < 0); + + // hashtable can store up to 3 uint8_t->uint64_t entries + av_assert0(!av_hashtable_alloc(&ctx, sizeof(k), sizeof(v), 3)); + + // unsuccessful deletes return 0 + k = 1; + av_assert0(!av_hashtable_delete(ctx, &k)); + + // unsuccessful gets return 0 + k = 1; + av_assert0(!av_hashtable_get(ctx, &k, &v)); + + // successful sets returns 1 + k = 1; + v = 1; + av_assert0(av_hashtable_set(ctx, &k, &v)); + + // get should now contain 1 + k = 1; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 1); + + // updating sets should return 1 + k = 1; + v = 2; + av_assert0(av_hashtable_set(ctx, &k, &v)); + + // get should now contain 2 + k = 1; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 2); + + // fill the table + k = 2; + v = 2; + av_assert0(av_hashtable_set(ctx, &k, &v)); + k = 3; + v = 3; + av_assert0(av_hashtable_set(ctx, &k, &v)); + + // inserting sets on a full table should return 0 + k = 4; + v = 4; + av_assert0(!av_hashtable_set(ctx, &k, &v)); + + // updating sets on a full table should return 1 + k = 1; + v = 4; + av_assert0(av_hashtable_set(ctx, &k, &v)); + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 4); + + // successful deletes should return 1 + k = 1; + av_assert0(av_hashtable_delete(ctx, &k)); + + // get should now return 0 + av_assert0(!av_hashtable_get(ctx, &k, &v)); + + // sanity check remaining keys + k = 2; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 2); + k = 3; + v = 0; + av_assert0(av_hashtable_get(ctx, &k, &v)); + av_assert0(v == 3); + + av_hashtable_freep(&ctx); + + return 0; +} -- 2.43.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".